Hello, I once was a regular player before the f2p, and I had the mines of Moria expansion. As I usually do, I have forgotten both username and password of the previous account. My question is, now that I have made a new free2play account, will I be able to play the mines of Moria I bought? (retail version). The expansion was installed in the previous account.
Once you apply a code to an account it is tied to that account only and can not be used again. So, no, the new account will not have the Mines of Moria expansion unless you purchase it again and apply the new code to the new account.
Unless you were a Codemasters (EU) customer and did not migrate the account to Turbine last year, you should first try recovering the username/password for your original account. That way you not only get your characters back, you also have any expansions you purchased and will start off at Premium rather than Free.